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7f983ba9 LPC |
1 | /* |
2 | * Copyright (C) 2009-2010, Lars-Peter Clausen <lars@metafoo.de> | |
3 | * JZ4740 SoC HWMON driver | |
4 | * | |
5 | * This program is free software; you can redistribute it and/or modify it | |
6 | * under the terms of the GNU General Public License as published by the | |
7 | * Free Software Foundation; either version 2 of the License, or (at your | |
8 | * option) any later version. | |
9 | * | |
10 | * You should have received a copy of the GNU General Public License along | |
11 | * with this program; if not, write to the Free Software Foundation, Inc., | |
12 | * 675 Mass Ave, Cambridge, MA 02139, USA. | |
13 | * | |
14 | */ | |
15 | ||
16 | #include <linux/err.h> | |
17 | #include <linux/interrupt.h> | |
18 | #include <linux/kernel.h> | |
19 | #include <linux/module.h> | |
20 | #include <linux/mutex.h> | |
21 | #include <linux/platform_device.h> | |
22 | #include <linux/slab.h> | |
23 | ||
24 | #include <linux/completion.h> | |
25 | #include <linux/mfd/core.h> | |
26 | ||
27 | #include <linux/hwmon.h> | |
28 | ||
29 | struct jz4740_hwmon { | |
30 | struct resource *mem; | |
31 | void __iomem *base; | |
32 | ||
33 | int irq; | |
34 | ||
e9300066 | 35 | const struct mfd_cell *cell; |
7f983ba9 LPC |
36 | struct device *hwmon; |
37 | ||
38 | struct completion read_completion; | |
39 | ||
40 | struct mutex lock; | |
41 | }; | |
42 | ||
43 | static ssize_t jz4740_hwmon_show_name(struct device *dev, | |
44 | struct device_attribute *dev_attr, char *buf) | |
45 | { | |
46 | return sprintf(buf, "jz4740\n"); | |
47 | } | |
48 | ||
49 | static irqreturn_t jz4740_hwmon_irq(int irq, void *data) | |
50 | { | |
51 | struct jz4740_hwmon *hwmon = data; | |
52 | ||
53 | complete(&hwmon->read_completion); | |
54 | return IRQ_HANDLED; | |
55 | } | |
56 | ||
57 | static ssize_t jz4740_hwmon_read_adcin(struct device *dev, | |
58 | struct device_attribute *dev_attr, char *buf) | |
59 | { | |
60 | struct jz4740_hwmon *hwmon = dev_get_drvdata(dev); | |
61 | struct completion *completion = &hwmon->read_completion; | |
62 | unsigned long t; | |
63 | unsigned long val; | |
64 | int ret; | |
65 | ||
66 | mutex_lock(&hwmon->lock); | |
67 | ||
68 | INIT_COMPLETION(*completion); | |
69 | ||
70 | enable_irq(hwmon->irq); | |
71 | hwmon->cell->enable(to_platform_device(dev)); | |
72 | ||
73 | t = wait_for_completion_interruptible_timeout(completion, HZ); | |
74 | ||
75 | if (t > 0) { | |
76 | val = readw(hwmon->base) & 0xfff; | |
77 | val = (val * 3300) >> 12; | |
78 | ret = sprintf(buf, "%lu\n", val); | |
79 | } else { | |
80 | ret = t ? t : -ETIMEDOUT; | |
81 | } | |
82 | ||
83 | hwmon->cell->disable(to_platform_device(dev)); | |
84 | disable_irq(hwmon->irq); | |
85 | ||
86 | mutex_unlock(&hwmon->lock); | |
87 | ||
88 | return ret; | |
89 | } | |
90 | ||
91 | static DEVICE_ATTR(name, S_IRUGO, jz4740_hwmon_show_name, NULL); | |
92 | static DEVICE_ATTR(in0_input, S_IRUGO, jz4740_hwmon_read_adcin, NULL); | |
93 | ||
94 | static struct attribute *jz4740_hwmon_attributes[] = { | |
95 | &dev_attr_name.attr, | |
96 | &dev_attr_in0_input.attr, | |
97 | NULL | |
98 | }; | |
99 | ||
100 | static const struct attribute_group jz4740_hwmon_attr_group = { | |
101 | .attrs = jz4740_hwmon_attributes, | |
102 | }; | |
103 | ||
104 | static int __devinit jz4740_hwmon_probe(struct platform_device *pdev) | |
105 | { | |
106 | int ret; | |
107 | struct jz4740_hwmon *hwmon; | |
108 | ||
109 | hwmon = kmalloc(sizeof(*hwmon), GFP_KERNEL); | |
110 | if (!hwmon) { | |
111 | dev_err(&pdev->dev, "Failed to allocate driver structure\n"); | |
112 | return -ENOMEM; | |
113 | } | |
114 | ||
6a54ac21 | 115 | hwmon->cell = mfd_get_cell(pdev); |
7f983ba9 LPC |
116 | |
117 | hwmon->irq = platform_get_irq(pdev, 0); | |
118 | if (hwmon->irq < 0) { | |
119 | ret = hwmon->irq; | |
120 | dev_err(&pdev->dev, "Failed to get platform irq: %d\n", ret); | |
121 | goto err_free; | |
122 | } | |
123 | ||
124 | hwmon->mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
125 | if (!hwmon->mem) { | |
126 | ret = -ENOENT; | |
127 | dev_err(&pdev->dev, "Failed to get platform mmio resource\n"); | |
128 | goto err_free; | |
129 | } | |
130 | ||
131 | hwmon->mem = request_mem_region(hwmon->mem->start, | |
132 | resource_size(hwmon->mem), pdev->name); | |
133 | if (!hwmon->mem) { | |
134 | ret = -EBUSY; | |
135 | dev_err(&pdev->dev, "Failed to request mmio memory region\n"); | |
136 | goto err_free; | |
137 | } | |
138 | ||
139 | hwmon->base = ioremap_nocache(hwmon->mem->start, | |
140 | resource_size(hwmon->mem)); | |
141 | if (!hwmon->base) { | |
142 | ret = -EBUSY; | |
143 | dev_err(&pdev->dev, "Failed to ioremap mmio memory\n"); | |
144 | goto err_release_mem_region; | |
145 | } | |
146 | ||
147 | init_completion(&hwmon->read_completion); | |
148 | mutex_init(&hwmon->lock); | |
149 | ||
150 | platform_set_drvdata(pdev, hwmon); | |
151 | ||
152 | ret = request_irq(hwmon->irq, jz4740_hwmon_irq, 0, pdev->name, hwmon); | |
153 | if (ret) { | |
154 | dev_err(&pdev->dev, "Failed to request irq: %d\n", ret); | |
155 | goto err_iounmap; | |
156 | } | |
157 | disable_irq(hwmon->irq); | |
158 | ||
159 | ret = sysfs_create_group(&pdev->dev.kobj, &jz4740_hwmon_attr_group); | |
160 | if (ret) { | |
161 | dev_err(&pdev->dev, "Failed to create sysfs group: %d\n", ret); | |
162 | goto err_free_irq; | |
163 | } | |
164 | ||
165 | hwmon->hwmon = hwmon_device_register(&pdev->dev); | |
166 | if (IS_ERR(hwmon->hwmon)) { | |
167 | ret = PTR_ERR(hwmon->hwmon); | |
168 | goto err_remove_file; | |
169 | } | |
170 | ||
171 | return 0; | |
172 | ||
173 | err_remove_file: | |
174 | sysfs_remove_group(&pdev->dev.kobj, &jz4740_hwmon_attr_group); | |
175 | err_free_irq: | |
176 | free_irq(hwmon->irq, hwmon); | |
177 | err_iounmap: | |
178 | platform_set_drvdata(pdev, NULL); | |
179 | iounmap(hwmon->base); | |
180 | err_release_mem_region: | |
181 | release_mem_region(hwmon->mem->start, resource_size(hwmon->mem)); | |
182 | err_free: | |
183 | kfree(hwmon); | |
184 | ||
185 | return ret; | |
186 | } | |
187 | ||
188 | static int __devexit jz4740_hwmon_remove(struct platform_device *pdev) | |
189 | { | |
190 | struct jz4740_hwmon *hwmon = platform_get_drvdata(pdev); | |
191 | ||
192 | hwmon_device_unregister(hwmon->hwmon); | |
193 | sysfs_remove_group(&pdev->dev.kobj, &jz4740_hwmon_attr_group); | |
194 | ||
195 | free_irq(hwmon->irq, hwmon); | |
196 | ||
197 | iounmap(hwmon->base); | |
198 | release_mem_region(hwmon->mem->start, resource_size(hwmon->mem)); | |
199 | ||
200 | platform_set_drvdata(pdev, NULL); | |
201 | kfree(hwmon); | |
202 | ||
203 | return 0; | |
204 | } | |
205 | ||
206 | struct platform_driver jz4740_hwmon_driver = { | |
207 | .probe = jz4740_hwmon_probe, | |
208 | .remove = __devexit_p(jz4740_hwmon_remove), | |
209 | .driver = { | |
210 | .name = "jz4740-hwmon", | |
211 | .owner = THIS_MODULE, | |
212 | }, | |
213 | }; | |
214 | ||
25a236a5 | 215 | module_platform_driver(jz4740_hwmon_driver); |
7f983ba9 LPC |
216 | |
217 | MODULE_DESCRIPTION("JZ4740 SoC HWMON driver"); | |
218 | MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>"); | |
219 | MODULE_LICENSE("GPL"); | |
220 | MODULE_ALIAS("platform:jz4740-hwmon"); |